1. Field of the Invention
The present invention relates in general to golf clubs. In particular, the present invention relates to a golf club having a club head with cavity for securing a removable insert which imparts spin to a golf ball.
2. Description of the Related Art
Most golf clubs, often referred to as irons and woods, have a substantially planar club face surface for striking a golf ball. Typically, this club face contains a frictional element or surface roughness that imparts a rotational spin to the golf ball upon contact. As known by golfers the world over, excessive spin of the golf ball is not desirable on a drive since it may cause a slice or a hook. However, spin of the golf ball, preferably backspin, is desirable on shorter shots to control the ball's flight trajectory and to minimize the ball's rolling distance after the ball lands on the green.
Typically, most golf clubs impart some form of spin. Even if the club face hits the ball flat, the horizontal and vertical grooves or other face irregularities on the striking face on the driver or woods may still impart a slight spin. Furthermore, those clubs with more loft such as the number 7, 8, 9 clubs and the wedges are intended to impart more backspin and increase the trajectory height of a ball in an effort to minimize the ball's rolling distance after it lands on the green. Again, to do this such clubs typically include horizontal grooves within the club face. Additionally, a grit containing hard particles or a coating of plastic adhesive may be applied to the club face to provide greater friction between the ball and the club face. Thus, a conventional golf club, particularly one for shorter shots, includes some combination of horizontal grooves and frictional finishes for imparting backspin to a golf ball.
Several disadvantages exist with the conventional golf club's grooves and frictional finishes. For example, the frictional finish's useful life may be relatively short. Once the coating wears off, the grooves provide the only practical means of introducing backspin. As a result, a golfer must periodically purchase a new club to maintain the proper frictional element on the club face. For most golfers, the grooves alone are insufficient for achieving the desired backspin.
Another disadvantage is that the frictional element of a new conventional golf club may be insufficient for the novice to obtain a desirable backspin. Most new golf clubs contain a standard degree of surface roughness. The standard roughness usually complies with the golf professionals' governing body, the United States Golf Association ("USGA"). The USGA's club roughness standard serves the useful purpose of assuring that all golfers participating in golf tournaments use similar type clubs. The USGA standards, however, are not particularly useful for the weekend golf warrior facing an island green with a conventional pitching wedge. As a result of conventional golf clubs complying with the USGA standard, many golfers need greater surface roughness on their club faces then presently available on new golf clubs.
Similarly, because a conventional golf club's surface roughness is standardized, it is difficult for one club surface to sufficiently accommodate all playing conditions and all golfers. For example, on a day when the greens are hard and dry, a golfer will need to put more backspin on the ball to make it stick on the green. Under such conditions, a golfer desires a club face surface with more roughness so the club imparts as much backspin as possible to the ball. In contrast, on a wet or damp day when the greens are soft and slow, a golfer will need less backspin and thus will need a less rough club face. Although a professional golfer is adept at using a single roughness club under varying course conditions, most golfers would prefer to have club faces with varying degrees of surface roughness to achieve a desired backspin under all conditions. Thus, a golfer must purchase several clubs, each for use under a different condition.
Prior patents have realized the advantages of greater surface roughness on the club face surface by adhering carbides and other hard particles to the striking surface of golf clubs. For example, in U.S. Pat. No. 4,917,384 to Caiati there is a disclosure of adhering diamond particles directly to the club face of a smooth driver face, that is, one without grooves. However, the Caiati golf club, like a conventional golf club, loses its surface roughness over time. Moreover, because the Caiati club face does not contain grooves, but rather is smooth prior to adhering particles, it is of little use to the golfer when the particles wear off. The golfer must either purchase a new golf club or adhere new diamond particles. Additionally, because the particles are permanently adhered to the club face, the golfer may need to purchase several clubs of differing roughness to achieve a desired backspin. See also Australian Patent Specification No. 268181.
Similarly, U.S. Pat. No. 4,768,787 to Shira discloses embedding hard particles into the golf club face. Although embedding particles has the advantage of longer roughness life then adhering particles to the golf club face, it still suffers from the disadvantage of requiring the golfer to purchase several different clubs of varying roughness.
Similarly, U.S. Pat. Nos. 5,688,190 and 5,690,561 disclose removable adhesive-backed onserts for placement on the existing face of the conventional club for additional backspin.
However, the need exists for a simple and effective way of providing additional flexibility to an existing set of golf clubs enabling the user to customize the clubs to their particular needs based on skill of the player and course conditions.